Knee pad



FIG. 1 is a front, left side perspective view of a knee pad, showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof, with the right side view being identical thereto;

FIG. 4 is a back view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

I claim the ornamental design for a knee pad, as shown and described. 